1. FIELD OF THE INVENTION
The present invention relates to a contact bar of textile machines, including a plurality of bar shaped bodies extending parallel to each other, which bar shaped bodies are insulated against each other and are connected to a power source and extend collectively through the contact slots of a plurality of drop wires arranged on the warp ends, which bar shaped bodies are insulated against each other and will be connected electrically by a drop wire upon a break of a warp end such to trigger a stopping of the machine, of which bar shaped bodies one is divided in longitudinal direction thereof into portions which are electrically insulated against each other allowing a localizing of the drop wire which triggered the stopping of the machine in one of the mentioned portions.
2. DESCRIPTION OF THE PRIOR ART
The bar shaped bodies of known apparatuses of this kind for the electrical warp stop motion consist of an outer bar having a U-shaped cross-section and an inner bar located therewithin in an insulated manner which, however, is divided into portions which are electrically insulated against each other. The outer bar is connected to the one pole of a power source and the portions of the inner bar which are insulated against each other are connected in parallel to the other pole of the power source via a main line and a series of distribution points as well as the branch lines which are branched off thereof. A control lamp is located at every respective bar partition area between adjacent portions and the lamps are respectively connected electrically to the adjoining distribution points, whereby due to the electrical circuit the two lamps at the ends of mentioned portion will be illuminated upon a drop of the drop wire onto said portion such that a detection can be made of that portion where which a warp has broken. An apparatus of this kind is disclosed in the German Utility Model DE-GM No. 80 10 814.
In a further apparatus of this kind as disclosed in the German Patent Specification DE-PS No. 32 10 333 the monitoring lamps allocated to the individual partition areas of the bar portions are not connected to parallel, there rather are provided light emitting diodes bridging the partition areas and connected electrically in series. Furthermore, a partition area and an allocated light emitting diode are located at the begin of the bar, such that the drop of a drop wire in this section, too, may be detected by the illumination of the first diode.
The drawback of these known apparatuses is the necessity of providing connections for lines to the control lamps or light emitting diodes, resp. at all partition area between the portions of the bar. In view of the rough operation of a textile mill and of the vibrations which the equipment for the warp stop motion must experience the arranging of lamps or light emitting diodes along a plurality of contact bars, having a length of several meters and located adjacent of and parallel to each other in an apparatus for the warp stop motion is quite unsuitable. If the light emitting diodes or the lamps are not installed directly above the contact bar but rather at a different location, it is necessary to lead lines from all bar portions and bridging the partition areas to the light emitting diodes located at a more distant or better protected, resp. location. Lines leading from the individual bar portions form also no advantageous solution, they rather cause such an apparatus or arrangement, resp. to be still more prone to disturbances.